Add translation CI validation

[Softer]

Fix broken localization in global_menu.py:505: tr(f'Invalid configuration: {error}') evaluates the f-string before tr() runs, so the translation catalog never matches. Switched to tr('...{}').format(...) and updated the msgid in base.pot.

Add scripts/pot_tools.py developer utility: stats, list, add_missing [--dry-run] for managing base.pot.

Add translation-check CI workflow with two jobs:

• validate-po (on .po changes): msgfmt --check on changed .po files, .mo sync warning. On .py changes: grep for tr(f"...") anti-pattern.
• validate-pot (on .py changes): verify all tr() strings exist in base.pot.
• Workflow triggers only on .py/.po/.pot file changes — no unnecessary runs.

Context

The previous translation-check workflow (added 2023, removed in #4483) failed because it validated all 35 languages on every PR, causing merge conflicts between translators. This new workflow checks only changed files and separates .po validation from .pot freshness checks.

[Softer]

I summon @svartkanin for discussion :-)

[svartkanin]

I'll have a look at it when I get some time

[svartkanin]

Lets not roll our own parser, there is msgcmp to do this

[svartkanin]

Don't use manual appending msgcat and msgmerge

[svartkanin]

why is this implemented twice?
Also please do not do this. You are hand rolling your own parser which firstly is not trivital and secondly doesn't work as it doesn't handle multi line messages.

[svartkanin]

This is already part of

archinstall/archinstall/locales/locales_generator.sh

Line 43 in b5501d9

find . -type f -iname "*.py" | xargs xgettext --join-existing --no-location --omit-header --keyword='tr' -d base -o locales/base.pot

We shouldn't create multiple scripts for doing the same thing. Either we enhance the existing one or we replace it.

[svartkanin]

There are a lot of things happening here. As pointed out there is already a helper script for minimal things

archinstall/archinstall/locales/locales_generator.sh

Line 43 in b5501d9

find . -type f -iname "*.py" | xargs xgettext --join-existing --no-location --omit-header --keyword='tr' -d base -o locales/base.pot

. I'd prefer if we either enhance that or replace it.
But given that there are a lot of moving pieces can we please do this iteratively with multiple smaller PRs.

In addition, please do not roll your own parser. It is not trivial and prone to edge cases that are difficult to handle. There are already existing tools msg* available that allow you to do everything you want.

[Softer]

Is it better now?

[svartkanin]

We can simplify this even more, for example

jobs:
    translations:
        name: Validate translations
        runs-on: ubuntu-latest
        steps:
            - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6
            - name: Install gettext
              run: sudo apt-get update && sudo apt-get install -y gettext

            - name: Validate .po syntax
              run: |
                  set -e
                  find archinstall/locales -name '*.po' -print0 \
                      | xargs -0 -n1 msgfmt --check --output-file=/dev/null

            - name: Reject tr(f-string) anti-pattern
              run: |
                  if grep -rnE "tr\(\s*f['\"]" archinstall --include='*.py'; then
                      echo "::error::Use tr('...{}').format(...) instead of tr(f'...')"
                      exit 1
                  fi

            - name: Verify base.pot is up to date
              run: |
                  cp archinstall/locales/base.pot /tmp/committed.pot
                  ( cd archinstall && find . -type f -iname '*.py' \
                      | xargs xgettext --no-location --omit-header --keyword=tr \
                            -d base -o locales/base.pot )
                  if ! diff -q /tmp/committed.pot archinstall/locales/base.pot; then
                      echo "::error::base.pot is out of date - run archinstall/locales/locales_generator.sh all"
                      diff -u /tmp/committed.pot archinstall/locales/base.pot || true
                      exit 1
                  fi

All these checks are only in the GH action which makes them difficult to test, so I suggest to put these into the already existing locale_generator.sh file and call them from here. That means during dev they can actually be called and tested and there is a single source of truth.
At that point this whole action can be reduced to

jobs:
    translations:
        name: Validate translations
        runs-on: ubuntu-latest
        steps:
            - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6
            - name: Install gettext
              run: sudo apt-get update && sudo apt-get install -y gettext
            - name: Run translation checks
              run: bash archinstall/locales/locales_generator.sh check

and the checks implemented in the bash file instead. As an example you can then have this in the script

...
cmd_check_no_tr_fstring() {
	echo "Checking for tr(f-string) anti-pattern..."
	if grep -rnE "tr\(\s*f['\"]" . --include='*.py'; then
		echo "ERROR: use tr('...{}').format(...) instead of tr(f'...')" >&2
		return 1
	fi
}

cmd_check() {
	cmd_check_no_tr_fstring
     ...
	echo "All translation checks passed."
}

case "${1}" in
	check)    shift; cmd_check "$@" ;;
	generate) shift; cmd_generate "$@" ;;
	-h|--help) usage ;;
	*)        cmd_generate "$@" ;;  # back-compat: bare `<lang>` means generate
esac